Table 4.

CO involved in plant abiotic stress tolerance.

Plant Species	Abiotic Stress and Its Effect	CO Roles under Stress	Reference
Alfalfa	Cd stress destroyed antioxidation enzymatic activities	Modulating glutathione metabolism	[57]
Alfalfa	Cd induced a loss of plasma membrane integrity, lipid peroxidation	Upregulating expression of HO-1 gene	[106]
Rapeseed	Hg stress inhibited growth and development	Improving antioxidation capacity and expression of BnHO-1	[3]
Mustard	Hg triggered production of O2⋅− and H2O2, as well as peroxides	Improving antioxidative enzymes, reducing oxidative stress	[107]
Rice	Zn stress inhibited root elongation	Downregulating of the expression of homeostasis-related genes	[108]
Wheat	Salt stress induced oxidative damage	Enhancing the activities of antioxidant enzymes	[109]
Wheat	Salt stress caused oxidative damage	Counteracting lipid peroxidation	[110]
Rice	Salt stress inhibited seed germination	Alleviating oxidative damage	[111]
Wheat	Salt stress reduced antioxidant enzyme activities	Decreasing of superoxide anion overproduction	[112]
Cassia obtusifolia L.	Salt stress lowered chlorophyll concentration	Alleviating oxidative damage, improving membrane permeability	[113]
Soybean	Salt stress affected the parameters of lipid peroxidation	Improving lipid peroxidation and ureide metabolism	[58]
Wheat	Osmotic stress-induced seed germination inhibition	Increasing in the activities of amylase and antioxidant enzyme	[114]
Rice	Drought stress inhibited HO activity	Improving the level of HO-1 gene expression and HO activity	[115]
Canola	Temperature stress delayed plant development	Enhancing the expression of BnDHN types gene	[15]